With nearly every county reporting — Pueblo County is the only major county yet to report — Romanoff held a 51 percent to 42 percent lead over Bennet. Seven percent of caucus-goers said they were uncommitted.

In a news release, Romanoff declared victory, calling the results a “shock wave” and said they reflect voter resentment of Washington politics and the big-money interests that contribute to it. The latter is a not-so-subtle shot at Bennet’s campaign coffers, which dwarf Romanoff’s.

“We’re very encouraged by these results,” Romanoff said. “This is the first chance Main Street has had to weigh in. We’ve already heard from Washington and Wall Street.”

Bennet’s campaign also called the results a victory, arguing that Romanoff’s margin of victory wasn’t as wide as they had expected. Craig Hughes, Bennet’s campaign manager, said Romanoff’s lengthy history of working within the state’s Democratic Party account for his strength with the party activists who make up most caucus-goers.

Bennet, in a news release, said he was looking forward to the primary.

“As someone who isn’t a political insider, tonight’s support is especially meaningful,” Bennet said.

Romanoff scored the biggest coup of the night when he decisively won the preference polls taken in Denver precincts, 60 percent to 35 percent. That has helped him for the present to push away from Bennet in what had been a neck-and-neck contest during the night’s earliest returns.

Bennet, though, has scored decisive wins of his own — most notably in Larimer County, where he won 58 percent to 38 percent. He also edged Romanoff in the Democratic stronghold of Boulder County, winning 47 percent to 46 percent.

Neither candidate appeared to have an advantage in any particular corner of the state, as both have won counties in the mountains, the Eastern plains and southern Colorado.

The main purpose of the caucuses is to begin the delegate-selection process that ends at the Democratic and Republican party assemblies in May. Candidates who receive at least 30 percent of delegates’ votes at those assemblies make the ballot for August’s primary elections. Candidates who participate in the process but fall short of 30 percent would have to petition to be onto the primary ballot.

Most importantly, the caucuses provided the best chance yet for candidates to gauge support among voters. As such, candidates for weeks have worked insider channels — via direct mailings, automated phone calls and old-fashioned face-to-face contact — to woo the most die-hard members of their party that make up the caucuses’ participants.

“Clearly the candidates think this is important,” said Denver pollster Floyd Ciruli.

But it was also clear Tuesday evening that the caucuses meant more to some candidates than others.

In the Democratic Senate race, for instance, Romanoff spent the last hours before the caucuses conducting interviews and visiting with party members.

“I expect we will do fine,” Romanoff said. “…This is the first step in a long journey toward the nomination.”

Bennet, by contrast, remained at work in Washington. Bennet campaign manager Craig Hughes said Bennet used the caucus process to bolster his campaign network but placed less emphasis on the outcome.

“The caucus has been a great opportunity to do retail politics up close and build enthusiasm around the state,” Hughes said.

Such a pattern suits the race’s theme, said Democratic political consultant Steve Welchert. Romanoff has campaigned as a candidate of the grassroots — making the caucuses a chance to prove himself to voters — while Bennet has focused on the larger electorate.

“This is (Romanoff’s) chance to show that his challenge is worthy of their support,” Welchert said.

Both candidates have tried to position themselves as outside-the-beltway choices.

“I tell people all the time, ‘If you like the way Washington works, you should vote for somebody else,'” Romanoff said.

Bennet touched on the same themes in his first campaign commercial, unveiled today.

“I’ve been in Washington for only a year, but it didn’t take that long to see the whole place is broken,” Bennet says in the ad.

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